Money: You can go on some micro quests and earn some cash and kill everything that moves and sell their items. Basically scrimp and save for quite a few levels until you get enough cash to get ONE PC in a Guild and then start over again or.............cheat.
Not too sure about the potion. I never gave it to him and I'm not too sure I ever had it. Sounds like a micro quest.
Party Construction:
This I did not give much thought too. I picked three fighters (Lizard Man, ?Warthog? and Felpurr) and three spell casters (?Elf? Fairy and an Omphaz or whatever). I'm about half way through the game and I had decided not to change class with my PC's. I don't see the point. I have not "yet" found the need for a lockpicker or a musician. If I play the game again, I'm going to try it with all spellcasters. That is if they can wear the Dragon Armor.